A hiker sees a lightning flash; 18 s later he hears the sound of the thunder. Recalling from his study of physics that the speed of sound in air is approximately (1/3) km/s. Calculate the distance of lightning flash. [ Assume that speed of sound is negligible as compared to speed of light] (7 pts)

Isobars are lines of constant or equal pressure on a weather map. they can be used to find areas of low or high pressure over a broad area, and they can tell us how intense the system may be. on weather maps, you may have noticed areas that have a large l or h over a region with lines circling around them. the l stands for low pressure and h stands for high pressure. the lines circling them are isobars. check out the pressure system and isobars over georgia and florida. what is the present weather in this area ? a) clear and sunny b) cold and cloudy c) changing weather d) lots of precipitation